From 01b172b7b10146cf5f02604047bee065cfb49946 Mon Sep 17 00:00:00 2001
From: Bob Peterson <rpeterso@redhat.com>
Date: Wed, 12 Mar 2014 10:32:20 -0400
Subject: [PATCH] GFS2: Ensure workqueue is scheduled after noexp request
This patch closes a small timing window whereby a request to hold the
transaction glock can get stuck. The problem is that after the DLM has
granted the lock, it can get into a state whereby it doesn't transition
the glock to a held state, due to not having requeued the glock state
machine to finish the transition.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
---
fs/gfs2/glock.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)
diff --git a/fs/gfs2/glock.c b/fs/gfs2/glock.c
index 52f747858f553..aec7f73832f08 100644
--- a/fs/gfs2/glock.c
+++ b/fs/gfs2/glock.c
@@ -1047,9 +1047,13 @@ int gfs2_glock_nq(struct gfs2_holder *gh)
spin_lock(&gl->gl_spin);
add_to_queue(gh);
- if ((LM_FLAG_NOEXP & gh->gh_flags) &&
- test_and_clear_bit(GLF_FROZEN, &gl->gl_flags))
+ if (unlikely((LM_FLAG_NOEXP & gh->gh_flags) &&
+ test_and_clear_bit(GLF_FROZEN, &gl->gl_flags))) {
set_bit(GLF_REPLY_PENDING, &gl->gl_flags);
+ gl->gl_lockref.count++;
+ if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0)
+ gl->gl_lockref.count--;
+ }
run_queue(gl, 1);
spin_unlock(&gl->gl_spin);